养护阶段环境作用对结构黏胶力学性能影响

结构黏胶是CFRP/钢补强体系的重要组成部分，易在环境作用下发生力学性能退化，从而影响整个补强体系的耐久性。结构黏胶一般需要两周左右的养护时间使强度得到充分发展，为了研究养护阶段不同环境作用对结构黏胶力学性能的影响，设计了4组共40个试件，考虑海洋大气环境、恒温恒湿环境和两种不同室内环境条件，研究结构黏胶吸水质量和力学性能的变化。试验结果表明，结构黏胶吸水质量随温湿度的提高而增加；与较高温度的室内常温环境相比，养护阶段在海洋大气环境与恒温恒湿环境作用下，结构黏胶的抗拉强度基本不变，但弹性模量显著降低，极限应变增加。

Effects of environmental exposure during curing stage on adhesive material properties

Structural adhesive plays an important part in the CFRP to steel bond interface. Its mechanical properties may deteriorate due to environmental conditions, leading to a detrimental effect on the strengthening system. Normally, it takes two weeks for the structural adhesive to achieve full strength. The effect of the environmental conditions during the curing stage on the mechanical properties is rarely reported and deserves further investigation. In this study, 40 adhesive coupon specimens were prepared and cured in four different environmental conditions for two weeks including marine atmosphere environment, constant temperature and humidity environment and two different kinds of room environments. The water absorption during the test period and the Mechanical properties of the adhesive after curing were recorded. Test results show that as the increase of the temperature and relative humidity, the water absorption is increased as well. In terms of the marine atmosphere and high relative humidity conditions adopted in the experiment, the ultimate tensile strength of the adhesive almost remains constant in comparison with the control specimens cured in the room condition II. However, an apparent softening of the adhesive is observed, i.e., the tensile modulus obviously decreases while the ultimate elongation increases.